As the next phase of Marvel’s movie master plan begins to unspool at theaters worldwide – with Thor on May 6 followed by Captain America: The First Avenger on July 22 – attention will quickly turn towards Joss Whedon‘s superhero crossover film The Avengers. And if we’re talking Avengers, screenwriter Zak Penn is a man in the know. Penn, who had a hand in writing X2, X-Men: The Last Stand, Elektra, The Incredible Hulk and even Last Action Hero, wrote the initial screenplay for The Avengers even before Whedon came on board. It’s been rumored that, once he did come on board, Whedon did a bunch of his own work on that script, but Penn still has a better idea than most about what we can expect from the film come May 4, 2012.

Several blogs tried to extract some of that Avengers knowledge from Penn as he was promoting a new SyFy series he created called Alphas and they were semi-successful. As is the case with huge movies like this, Penn has signed a non-disclosure agreement and can’t say much, but he did talk about his excitement over Whedon, writing the script and more. Read his quotes after the break.

Penn spoke with both Superhero Hype and Collider over the weekend and we’ve grabbed some quotes from both. Head over to each site for the full interviews.

First of all, Penn was open and upfront about the fact that he wouldn’t be able to say much:

I had to sign a non-disclosure agreement for The Avengers, so I can’t really speak about it too much. I’m pretty limited.

With that knowledge, he did comment on the development of the project since he’s left:

Do you believe in Joss Whedon? Do you believe in him? I believe in him! That’s my comment. If you believe in Joss you should be excited. Actually Joss and I went to the same college so we have a long history. I’m very excited. I can’t wait to see what happens with it, you know. And it’s weird because “Alphas” is kind of almost the inverse. If you know the comic book world, this is kind of the flipside of something like “The Avengers,” so it will be weird next year to have “Avengers” coming out while I’m working on this show.

He wasn’t able to comment on how much work Whedon did on his script, nor about how much input any of the actors were having, but Penn did talk about writing such a huge script under intense pressure and scrutiny from fans:

Well, you’ve got to try to not think about those things. You have to. A lot of times, the fans have pretty smart things to say about what they’d like to see. Quite often, their interpretation of why it wasn’t what they wanted it to be is a little skewed. A lot of times, people talk about why this movie or that movie is terrible, and I feel like, “That’s not why it was terrible. It was terrible for this reason.” But, I do think it’s valuable to know what it is that people want to see in the movie. Particularly on something like The Avengers, or the X-Men movies, it’s such a slippery slope. You’ve got to just try to put your head in the sand and write the best story you can. It is literally impossible to please everybody. You can’t please fans who don’t agree with each other anyway. You go read a message board and there’s 80 opinions about what should happen with every character. That’s a fool’s errand, so you try not to do it, but it is pretty hard.

Penn, a huge superhero fan, also spoke about his excitement over writing a script like this:

First of all, most of what was exciting about it, that I can tell you, was just the prospect that we would finally actually do a real cross-over movie, in which characters from multiple films were appearing at the same time, and it wasn’t just a cameo. To me, that was something very exciting. Even if it had ended up being The Vision, Giant-Man and two other characters, it still would have been cool. The idea that there’s these other movies being made, and they’re all working towards this one final goal is what excited me. That, we did spend many years working on. All the people at Marvel and me would sit there and say, “Okay, so this is what’s happening in Thor. This is what’s happening in Captain America. This is what’s happening here.” So, that was probably the most exciting part of it. I didn’t have the same pre-conceptions about what The Avengers movie should be that I did about X-Men. The Avengers can go a lot of different directions. There is no one line-up. If you did an X-Men movie and it didn’t have Professor Xavier in it, that would be a weird movie. There’s a lot that I’m excited for, but I can’t really talk about what’s in it, so I can’t tell you about what worked, what they listened to and what they didn’t. But, theoretically, it should be amazing.

It’s obvious that Penn is a huge fan with a passion for this material and his comments are pretty encouraging. Not that he would actually say anything bad about it, he did get a paycheck after all. For more of his comments on Alphas, Jeremy Renner and more, head over to Collider and Superhero Hype.

With Thor and Captain America coming soon, plus The Avengers getting ready to shoot, we’ll certainly to being to learn more and more about the film in the coming weeks. It’s scheduled for release May 4, 2012.